/****************************************************************************

**

** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

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**

** This file is part of the QLALR module of the Qt Toolkit.

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** No Commercial Usage

** This file contains pre-release code and may not be distributed.

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** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

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** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

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** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

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** $QT_END_LICENSE$

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****************************************************************************/

#include <cstdlib>

#include <cstdio>

enum Token {

    EOF_SYMBOL,

    LEFT_ANGLE,

    RIGHT_ANGLE,

    ANY,

};

static int current_char;

static int yytoken;

static bool in_tag = false;

bool parseXmlStream();

bool parseTagOrWord();

bool parseTagName();

inline int nextToken()

{

    current_char = fgetc(stdin);

    if (current_char == EOF) {

        return (yytoken = EOF_SYMBOL);

    } else if (current_char == '<') {

        in_tag = true;

        return (yytoken = LEFT_ANGLE);

    } else if (in_tag && current_char == '>') {

        in_tag = false;

        return (yytoken = RIGHT_ANGLE);

    }

    return (yytoken = ANY);

}

bool parse()

{

    nextToken();

    return parseXmlStream();

}

bool parseXmlStream()

{

    while (parseTagOrWord())

        ;

    return true;

}

bool parseTagOrWord()

{

    if (yytoken == LEFT_ANGLE) {

        nextToken();

        if (! parseTagName())

            return false;

        if (yytoken != RIGHT_ANGLE)

            return false;

        nextToken();

        fprintf (stderr, "*** found a tag\n");

    } else if (yytoken == ANY) {

        nextToken();

    } else {

        return false;

    }

    return true;

}

bool parseTagName()

{

    while (yytoken == ANY)

        nextToken();

    return true;

}

int main()

{

    if (parse())

        printf("OK\n");

    else

        printf("KO\n");

}